During dip coating of a substrate in for example a photosensitive coating solution, “burping” may occur when the coating solution contains a volatile solvent. This is because the volatile solvent evaporates from the coating solution and is trapped within the confines of the substrate interior, resulting in a pressure buildup. The resulting increase in pressure may cause a gas (typically air) to escape from inside the substrate shortly before it emerges from the coating solution. This escape of the gas typically causes a solution surface disturbance which may result in a nonuniform coating thickness on the substrate. There is a need, which the present invention addresses, for new methods and chuck assemblies to minimize or eliminate the “burping” phenomenon.
Conventional dip coating methods and chuck assemblies are described in the following:                Schmitt et al., U.S. Pat. No. 5,743,538;        Chambers et al., U.S. Pat. No. 5,853,813;        Godlove et al., U.S. Pat. No. 5,683,755;        Swain et al., U.S. Pat. No. 5,688,327; and        
Swain et al., U.S. Pat. No. 6,132,810.